Yes thats true....there is going to be times where that child will not have satisfactory supervision whilst using the net unfortunately. I wish there were tighter controls implemented so that children are more protected.
I dont agree with having a tag next to their name stating they are a minor though, I think this would be like a beacon to attract unsavioury characters! I have worked with childrens groups were the group leader insisted that the children wore name tags on outings....I was always against that aswell for a variety of reasons!